Finding the Fourth Proportional to 111.09, 153.30 and 72.28

Step by Step Solution

1. Step 1: Write the proportion equation
   111.09 : 153.30 = 72.28 : x
2. Step 2: Convert to fraction form
   111.09/153.30 = 72.28/x
3. Step 3: Cross multiply
   111.09x = 153.30 × 72.28
4. Step 4: Simplify right side
   111.09x = 11,080.52
5. Step 5: Solve for x
   x = 11,080.52/111.09
6. Step 6: Final answer
   x = 99.74